1. The Oesophagus

2. How does food get to the stomach?

3. The Oesophagus How does food travel along the oesophagus?

4. The Epiglottis

6. Mouth Stomach Muscles behind food contract Food Direction of food Muscles in front of food relax

7. The oesophagus Food is transported from the mouth to the stomach through the oesophagus. Food is pushed along the digestive tract by muscles; this process is known as peristalsis.

8. The Stomach

9. The Stomach Video http://www.ltscotland.org.uk/glowscience/hum an_body/digestion/film_185/index.html

10. The Stomach What are conditions like inside the stomach? Since the stomach is acidic which enzyme work wells?

11. The Stomach In what two ways does the stomach help to digest food?

12. The Stomach The stomach is a muscular bag which contracts to help mix the food with digestive juices. Pepsin is produced by the stomach. It breaks down protein into amino acids. The stomach is acidic to provide the optimum pH for pepsin activity.

13. The Stomach There is a ring of muscle found at the opening and exit of the stomach. The ring of muscles at the entrance stops stomach acid getting into the oesophagus. What happens if stomach acid does get into the oesophagus?

14. Heartburn

15. The Small Intestine

16. The start of the small intestine Liver Stomach Gall bladder Pancreas Small intestine 1 2 3 4 5

17. The Liver and the Gall Bladder The liver produces bile The gall bladder stores bile Bile splits big blobs of fat into smaller blobs which are easier for enzymes to digest

18. The Pancreas The pancreas produces and releases the enzyme lipase Lipase breaks down fats into fatty acids and glycerol

19. Now large insoluble food molecules have been broken down into small soluble molecules Carbohydrate e.g. starch Fat Protein Amylase LipasePepsin

23. The Small Intestine All the nutrients from digestion are absorbed by the small intestine The surface of the small intestine is covered in villi The Villi Villi increase the surface area of the small intestine. This means that more nutrients can be absorbed and faster.

24. Features of the villi Good Blood Supply The blood capillaries absorb simple sugars and amino acids Thin epithelium The skin of each villus is only one cell thick, this allows absorption to happen very fast. Lacteal The lacteal absorbs fatty acids and glycerol

25. The Large Intestine

26. Large Intestine Rectum Appendix Large intestine Appendix Rectum All that enters the large intestine is waste material and water.

27. The Large Intestine The large intestine absorbs excess water from the waste material The Rectum The rectum stores faeces until it is convenient to expel it